Anode



Nov. 18, 1941. H, J 'DNLEY 2,263,164

ANODE Filed Feb. 25, 1941 46 Z/ECO/V/U INVENTOB A. a. 0/9/45) AT ORNEYPatented Nov. 18, 1941 ANODE Hampton J. Dailey, Bloomfield, N. J.,assignor to Westinghouse Electric & Manufacturing Company, EastPittsburgh, Pa., a corporation of Pennsylvania Application February 25,1941, Serial No. 380,417

7 Claims.

My invention relates to discharge devices, and especially to the anodestructure therein.

An object of the invention is to provide an anodewith good gas-absorbingqualities.

A still further object of the invention is to a provide a gas-absorbinganode that is easi y fabricated to close dimensions and inexpensive.

Other objects and advantages of the invention will be apparent from thefollowing description and drawing in which:

Fig. 1 is an elevational view of a typical dis-' charge device embodyingmy invention.

Fig. 2 is a cross-sectional view through the anode of Fig. 1illustrating a preferred embodiment of my invention.

F18. 3 is an enlarged cross-sectional view of a small portion of theelectrode base and coating.

One or the problems in industrial tubes has.

- been the liberation-of gases during operation which change theoperating characteristics of the tube. Heretofore tantalum has beenutilized in view of its gas-absorbing qualities. Tantalum, however, avery expensive.

. It is an object of my invention to utilize zir-- conium because of itsgood gas-absorbing qualities. The zirconium, however, as heretoforeused,

ported in turn by certain cross insulators I1, I81

and i9. One of these cross insulatoiis [8 provides means for resilientlysupporting the cathode it with a spring 28 resiliently supporting a hook2|. for the upper part of the filament. A cross bar 22 in the lower partof the tube supports the grid structure on the lower reentrant press,and from this cross bar 22 is a connection 23 passing through press I las a grid lead.

The anode of my invention surrounds the cathode and grid structure. Thisanode 25 is preferably of the oval cross section disclosed in Fig. 2 andextends axially of the tube the distance of the effectiveelectron-emitting portion of the rather elongated in view of the shapeof the I cathode.

As disclosed in Fig. 2, the inner sides and 3| provide an extensiveelectron-receiving surface.-

In order to support the anode I preferably locate, eight projectingbosses on the upper and lower portions of both sides of the anode. Twoof these bosses 32 and 33 are on the upper portion of the anode inFig. 1and symmetrically spaced on each side of the longitudinal axis of thetube. The lower portion of the anode has two similar bosses 34 and 35aligned with the top bosses. The rear side of the anode has two similarbosses 36- and 31 on the upper portion and two similar bosses, notshown, on the lower portion. These bosses have aligned openings 38therethi'ough. Standards 40 are threaded through the aligned openings ineach upper and lower pair of bosses and standards 40 are secured in thebottom insulator scales of! easily and has proven unsatisfactory.

I9 as disclosed in Fig. 1. The upper ends ll of these standards are bentover to the reentrant press 42 at the upper end of the tube and securedthereto.. A connection 43 extends through 'the press to the anodeexterior connection It at the upper end of the tube. The exteriorconnections for the cathode and grid preferably extend through the lowerbase 45 of the tube.

In forming the anode I select amorous roughsurfaced material as a baseand fabricate itto the desired shape, such as disclosed in Figs. 1 and2. The material which I have found especially desirable is carbon in theform of graphite.

I then mix the zirconium powder with a binder or carrier and preferablyutilize a nitrocellulose binder because the volatile constituents areeasily baked out and the residue from the binder is essentiaily'carbon.The zirconium powder is preferably of about 325 mesh fineness, and afterbeing mixed with ,the binder, can be sprayed or painted on the outersurface 46 and inner surface 41 of the carbon base 48 of the anode.

melts on the electrode. The anode is then assembled in the tube.

I have found that no other baking was necescathode It. The anode has itsmain oval axis 5 sary than that used in exhausting the tube. One

, the zirconium layer.

minute at ,1200" C. induction treatment was usually suificient toeliminate visible ionization in the tube. The binder was baked out and.a firmly bonded zirconium'layer remained on the carbon anode. The carbonwith its'suriace pores well-filled with thezirconium film, provides alayer which does not easily flake ofi during operation. The firm bondbetween: the two is illustrated in the enlarged view in Fig. 3.

. If a metal base is desired, I roughen the surface, preferably by sandor carborundumblast ing, and then fill the artificially made pores withThe grid 85 may be coated with zirconium to reduce secondary emission.

My invention is also adapted for tubes utilizing mercury vapor as thezirconium absorbs the undesired gases;

My invention has accordingly produceda cheap zirconium on said porouscarbon base with the" portion of said coating contiguous to the baseembedded in the pores thereof.

3. The method of treating an electrode to have I gasrabsorbingproperties which. comprises selecting a base having large surface poresand filling ,said pores with zirconium.

4. The method of treating an electrode to have gas-absorbingpropertieswhich comprises select,- ing a base having largesurface'pores, filling said pores withzirconium powder and a binder andevaporating the binder. I I

to the porous material by portions of the coating.

' entering pores contiguous to said coating.

and easily fabricated anode with good gas-absorbing qualities.

Although I have shown and described a specific embodiment of myinvention, 1 do not desire to be limited thereto asva'rious othermodifications of the same may be made without departing from the spiritand scope of the appended claims.

i claim:

3.. An electrode for a discharge device comprising porous base and acoating of zirconium on saidporous'base with theportion of said coatingcontiguous to the base embedded in the pores thereof.

2. An electrode. for a discharge device comprising a porous carbon baseand a coating of "ening the exposedsuriface of ,ametal base for 6. Themethod of treating an electrode to have gas-absorbing properties whichcomprises selecting a base havingthe inherent characteristic of porousrough-surfaced material, and smoothing I the exposed surface by bothfilling the outer pores thereof and coating the surface with zirconium.

7. The method of treating an electrode to have gas-absorbingpropertieswhich comprises roughproducing artificial pores, and'smoothingthe roughened surface by both filling the said artificial pores andcoatingthe surface with airconium.

HAMPTON J. DAILEY.

